This proposal suggests the establishment of a prototype Alzheimer's disease patient registry in East Boston, Massachusetts, a geographically defined community. Data for the proposed registry will be obtained from already funded, large scale, community-based studies. Specified clinical diagnostic criteria will be uniformly applied to the defined registry population, and registry data will be handled and stored in an efficient manner. Clinical diagnoses will be correlated with neuropathological findings. Neuropathological examinations will be performed through the Massachusetts Alzheimer's Disease Research Center, and well considered steps to enhance autopsy rates for registry subjects will be taken at both the community and hospital levels. These data will be used to address a range of relevant issues for deciding if development of patient registries is feasible for Alzheimer's disease, and if so, to suggest the best solutions to these issues. In addition, as specified in the RFA, issues of wider interest outside of classical disease registry functions are addressed: The availability of data from unaffected individuals in the same existing study populations permits analyses of risk factors for Alzheimer's disease. Coordination with ongoing studies at the Hebrew Rehabilitation Center for Aged will permit the administration of selected identical diagnostic instruments to a large institutionalized population; cost of this testing is also covered by existing funding. The registry will be used to provide rigorous training opportunities for a limited number of selected candidates, and the training will include special attention to issues relevant to randomized clinical trials. Thus, the overall goal of the proposal is to both provide an optimal prototype registry and to meet the related aims of the RFA while making efficient use of existing large-scale data sources well suited to registry needs.